This invention relates to an apparatus for bending elongated materials, such as pipes and bars, in optional directions, characterized by inclusion of a bending head that moves about the material to define the bending direction.
For bending more than one portion of an elongated material in various directions, conventional apparatus have used a bending head that rotates about the material. Bending apparatus of this kind, for example, have been disclosed in U.S. Pat. No. 4,604,885 and U.S. Pat. No. 4,735,075. These conventional apparatus have a fixed chucking unit for chucking the material and feature a bending head that moves along the longitudinal axis of the material from one end portion to the chucking portion of the material. While moving along the material-axis, the bending head, stops at predetermined bending portions, and rotates about the material-axis to define the bending direction, thus bending the material in the defined direction.
On the other hand, if the material is to be bent using different bending radii at different bending portions, it is necessary to change the bending die of the bending head for each bending portion. The conventional bending apparatus, however, do not have a mechanism for moving the bending die closer to and farther away from the material. It is, therefore, impossible to exchange the bending die to allow different bending radii.
This prior art has another problem in that the material to be bent is near the chucking unit. Since the chucking unit obstructs the movement of the rotating mechanism for rotating the bending head, the bending head cannot be located near the chucking unit. Accordingly, bending is not possible near the chucking unit.